steering problems
 

I just put a new servo in my nitro truggy, and I ran it for the first time today, but I didn't run it long because the steering was acting funny. I could turn the truggy to the right and it would turn just fine, but when I turned it to the left and gave it some gas the steering would straighten up and the truggy wouldn't turn unless you let off the gas. What could be the problem with my truggy?